1. Field of the Invention
The present invention relates to a rotary magnetic head apparatus comprising a non-contact-type transmission apparatus for use in an information writing apparatus, such as a video tape recorder.
2. Description of the Related Art
Apparatuses for recording information onto a magnetic tape and reproducing information of a magnetic tape include video tape recorders, tape streamers, and the like. Such types of information writing apparatus comprise a rotary magnetic head apparatus for the purpose of recording a signal onto a magnetic tape and reproducing a signal of a magnetic tape.
The rotary magnetic head apparatus includes a rotary drum and a fixed drum, and the rotary drum includes a recording head and a reproduction head. The recording head is a head for recording a signal onto a magnetic tape, and the reproduction head is used to reproduce a signal recorded on a magnetic tape.
The rotary drum, which houses the recording head and the reproduction head, is rotated by the actuation of a motor with respect to the fixed drum, causing the recording head or the reproduction head to scan the magnetic tape, for example, by a helical scan method. Thus, information can be recorded onto a magnetic tape or information of a magnetic tape can be reproduced along the recording tracks by a tracking reproduction method.
By adopting such a helical scan method, high-density recording of a signal onto a magnetic tape is made possible, and the relative speed between the magnetic tape and the magnetic head can be increased.
In the rotary magnetic head apparatus of a helical scan method, since the recording head and the reproduction head are housed inside the rotary drum, signals and power must be exchanged between this rotary drum and a fixed drum by a non-contact method; for example, in the case when a reproduction signal obtained from the reproduction head is transmitted from the rotary drum to the fixed drum in a non-contact manner, or when power for a circuit substrate is supplied from the fixed drum to the rotary drum.
In this type of rotary magnetic head apparatus used in the conventional art, non-contact-type transmission of a signal system uses a rotary transformer dedicated to the signal system, and in order to supply power without contact, another rotary transformer for power supply is required. The reason why a rotary transformer of a signal system and another rotary transformer for power supply are prepared in this manner is to prevent crosstalk of a transmission signal used for the rotary transformer for power supply to the rotary transformer side of the signal system.
This crosstalk refers to leakage of a signal due to a leakage magnetic-field between the adjacent signal system and power-supply system or between different signal systems.
However, the rotary magnetic head apparatus comprising two rotary transformers is enlarged, the cost increases, and in addition it is difficult to mount two rotary transformers to a small rotary magnetic head apparatus.
Also, in the rotary transformer, often, one transmission channel of the rotary transformer is assigned to a respective reproduction heads and a reproduction signal system thereof. However, while there has been a demand for an increase in the amount of recording data and a higher transfer rate, it is expected that the number of reproduction heads mounted in a rotary drum and the number of channels of the reproduction signal system will be greater in the future. In the current situation where one transmission channel of the rotary transformer is assigned to one reproduction head and one reproduction signal system, the rotary transformer is enlarged, causing the rotary drum to is enlarged. Therefore, it is difficult to mount such a rotary magnetic head apparatus including a plurality of reproduction heads and reproduction head signal systems to a small information apparatus, and greater costs are incurred.
Accordingly, an object of the present invention, the achievement of which solves the above-described problems, is to provide a rotary magnetic head apparatus which can be formed into a small size even if a plurality of reproduction heads are provided.
To achieve the above-described object, according to the present invention, there is provided a rotary magnetic head apparatus which records a signal onto a tape-like information recording medium and reproduces a signal of a tape-like information recording medium, said rotary magnetic head apparatus comprising: a transmission apparatus for transmitting power and signals in a non-contact manner between a rotor and a stator; a rotary drum having a rotor of a transmission apparatus and a recording head; a fixed drum having a stator of a transmission apparatus and a plurality of reproduction heads; reproduction signal selection means for selecting a reproduction signal of the information recording medium obtained by each reproduction head and for arranging the reproduction signal in sequence; a rotor reproduction signal wiring section which is disposed in the rotor and to which is input a reproduction signal of each reproduction head, which reproduction signal is sent from the reproduction signal selection means; and a stator reproduction signal wiring section, which is disposed in the stator, for receiving a reproduction signal without contact from the rotor reproduction signal wiring section.
In the present invention, the rotary drum of the rotary magnetic head apparatus includes a rotor of a transmission apparatus and a recording head. The fixed drum of the rotary magnetic head apparatus includes a stator of the transmission apparatus and a plurality of reproduction heads. The reproduction signal selection means is capable of selecting a reproduction signal of an information recording medium, which reproduction signal is obtained by each reproduction head. Supplied to the rotor reproduction signal wiring section is a reproduction signal of each reproduction head, which signal is sent from the reproduction signal selection means. The stator reproduction signal wiring section is designed to receive the reproduction signal from each rotor reproduction signal wiring section without contact.
As a result of the above, since the reproduction signal obtained by a plurality of reproduction heads is selected and arranged in sequence by the reproduction signal selection means, it is not necessary to provide rotor reproduction signal wiring sections and stator reproduction signal wiring sections corresponding to the number of reproduction heads. That is, since the reproduction signal transmission system for a reproduction signal from each reproduction head, which reproduction signal is arranged by the reproduction signal selection means, needs to be prepared, for example, for one channel, it is possible to decrease the number of channels of the rotor reproduction signal wiring section and the stator reproduction signal wiring section for the purpose of transmission without contact.
The above and further objects, aspects and novel features of the invention will become more apparent from the following detailed description when read in connection with the accompanying drawings.